Adding oil to sealed automobile air conditoning system



W- C. KARNES Feb. 7, I96? ADDING OIL TO SEALED AUTOMOBILE AIR CONDITIONING SYSTEM Filed March 2, 1965 In v e n I o r I Wilbm O. Kcwnes ju /m United States Patent C) 3,302,421 ADDING OlllL T SEALED AUTOMOBILE AIR CUNDITONING SYSTEM Wilba C. Karnes, San Antonio, '][ex., assignor of one-half to Henry H. Sueiling, Chevy Chase, Md. Filed Mar. 2, 1965, Ser. No. 436,607 2 Claims. (Cl. 62-77) Brief summary For the servicing of automobile condensers, shops in the South frequently have the usual manifolds with high and low gauges connected to a Freon tank. The shop equipment may also include a separate vacuum pump. The present invention incorporates into the permanent service shop equipment a 3-way valve manually connecting selectively the vacuum pump or the Freon tank with the mid-portion of the manifold and adds an auxiliary tank sealed against the entry of air or moisture and connected temporarily with the automobile condenser to discharge into the latter selectively either a vacuum pressure or a moisture free oil.

This invention relates to air conditioning for automobiles and has for its principal object the provision of a sealed system in which either oil or refrigerant or both may conveniently be added as needed and one in which the oil being a completely dry oil having a high atfinity for moisture is only momentarily exposed to the atmosphere, as when the novel auxiliary tank to hold both refrigerant and oil is being filled.

A further object of the invention is to provide a system which is simple and is time saving as *with it there is no need, after removing all air and moisture following repairs, to connect and disconnect hoses or gauges until the procedure is completed and therefore a serviceman may, for example, add oil to an automobile air conditioning system, after repairing it, in a minimum of time and without any loss of the refrigerant, Freon being preferred, also without allowing entry of moisture or other contaminants into the system.

In the drawing the figure represents the system partly in section as it will be while adding oil subsequent to completion of the steps of removing air and moisture as is done following repair of the system.

The gauge set includes a manifold to which are secured a low pressure gauge 11 on the left end, and a high pressure gauge 12 on the right. Nipples 14, 15

-and 16 from the manifold through the usual couplings 17 lead respectively, left to right, to a hose 13 leading to an auxiliary tank 18; a hose 19 leading from the midportion 20 of the manifold selectively by a three-way valve 31 to either the Freon tank 21 or a vacuum pump 22; and lastly nipple 16 is secured to a hose 23 leading from the high or discharge side 24 of a compressor 26 to the portion of manifold 10 to the right of valve 27. This compressor is not part of the shop equipment as is the remainder of the parts illustrated.

Valve 27 operated by hand wheel 28 closes the high pressure side of the compressor. Valve 29 on the left or low pressure side of the manifold is operated by the hand wheel or knob 30 and has been open during the evacuating of the system. The low pressure gauge 11 registers the vacuum pressure in the upper space 40 of the auxiliary tank 18 when the valve 29 is closed and registers the Freon pressure when that valve is open.

The auxiliary tank 18, which is the novel element of the new combination, has a nipple 33 connected by pipe 13 to nipple 14 on the manifold 10 and to one side of its curved dome 34 has the usual filler cap 35. The tank 18 has a capacity of one quart as that is the size of the usual bottle of special oil. This allows the tank to be filled with minimum chance of moisture being admitted.

" ice A double valve 37-39 controlled by hand wheel 36 governs passage through valve 37 from auxiliary tank 18 to the suction line 38 of the compressor 26 or if it is closed and valve 39 is therefore open, from the top portion or space 40 of the auxiliary tank 18 through the vertical refrigerant charging tube 42 which has its upper open end in space 40 at the top of the dome 34. As later stated, valve 39 is open only during the vacuum step. The scale 44 reading in ounces of oil is readily visible, preferably with its zero mark at the level of the junction of the dome 34 and the cylindrical side to aid in determining how many ounces have been withdrawn.

While removing air and moisture, with the compressor not running, valve 37 at the bottom of auxiliary tank 18 is closed, nearby valve 39 is open, hence the vacuum line extends from the vacuum pump 22, the three-way valve 31, hose 19, open valve 29 in the manifold, hose 13, top space or chamber 40 of the auxiliary tank, vertical charging tube 42, through the open valve 39 to line 38 to the low or suction side 25 of the compressor, valve 48 being open. Valve 48 is closed only when the compressor is being removed from the shop equipment. When the desired low reading on gauge 11 is obtained, valve 27 in the manifold 10 is closed and the three-way valve 31 is moved to establish communication between hose 19 and the Freon tank 21 as in the figure.

After the vacuum treatment has been completed, and the valve 31 shifted to connect hose 19 to tank 21, the Freon or other refrigerant is admitted to the system. Valve 27 in the manifold is closed, valve 29 is open and the Freon therefore passes freely from tank 21 via hose 19, manifold midsection 24 open valve 29, into the top chamber 40 of the auxiliary tank. 18 and down through the charging tube 42, through the open valve 39, and pipe 38 to the low pressure side 25 of the compressor 26 and through hose 23 from the high or discharge side 24 of the compressor to the manifold 10 and high pressure gauge 12, valve 27 being closed. It is well to close valve 29 after the system is filled with Freon, then run the compressor a few minutes to stabilize the system. At this time the system is adequately filled with Freon gas but as shown in the figure a number of ounces of oil have previously been withdrawn from the system lowering the oil level in the compressor to the dotted line 48, the oil level in the auxiliary thank 18 remaining at its previous state.

To add the necessary oil, valve 39 is closed and valve 37 is thereby opened. The compressor is now started and by slightly opening valve 29 in the manifold the pressure of the Freon slowly forces oil into the compressor, the oil passing via open valve 37 and line 38 to the bottom of the compressor where its level therein is checked in the usual manner by removing the oil check plug 43. It is preferable to add the oil in small quantities, such as two ounces at a time, rather than making up the entire deficit at a single time.

As previously stated, the auxiliary tank 18 is a portion of the automobile repair shop equipment. When all work is completed, the shut-off valve 48 in hose 38 is closed and 3-way valve 31 turned to close Freon tank 21 from pipe 19 and now hoses 38 and 23 may be disconnected from the compressor by means of the usual quick connectors furnished with all automobile air conditioning systems.

What I claim is:

1. Apparatus for adding refrigerant and moisture-free oil to the compressor of an automobile air conditioning system, comprising an auxiliary receptacle for holding oil and refrigerant gas, a vacuum pump, a refrigerant supply tank, a manifold connected separately to the high or discharge side of the automobile compressor, the refrigerant supply tank, and the auxiliary tank; means for selectively connecting either the refrigerant supply tank or the vacuum pump with the mid-portion of the manifold, valve means closing the mid-portion of the manifold from each end thereof, an open topped vertical refrigerant charging tube within the auxiliary receptacle extending above the liquid level of the oil therein, piping connecting the bottom of the auxiliary receptacle with the suction side of the compressor, said piping including valve means for connecting the automobile compressor with either the charging tube to discharge refrigerant gas to the automobile compressor or to the bottom of the auxiliary receptacle to discharge oil to the compressor whereby oil may be discharged to the compressor without opening the system to the atmosphere.

2. The apparatus of claim 1 in which the auxiliary receptacle has a capacity of about a quart and has a filler cap to receive the usual bottle of special dry oil needed,

whereby permitting the receptacle to be filled with admission of a minimum amount of moisture; the means for selectively connecting includes a 3-Way valve and the valve means in said piping opens one passageway as it closes the other so that moisture-free oil or vacuum pressure alone may be admitted to the connected automobile compressor, and the vertical refrigerant charging pipe is directly connected to the valve means in the piping.

References Cited by the Examiner UNITED STATES PATENTS 3,081,605 3/1963 Leonard 62--4-75 X 3,093,979 6/1963 Ehrens et al 6277 X 3,225,554 12/1965 Alexander 62-149 X LLOYD L. KING, Primary Examiner. 

1. APPARATUS FOR ADDING REFRIGERANT AND MOISTURE-FREE OIL TO THE COMPRESSOR OF AN AUTOMOBILE AIR CONDITIONING SYSTEM, COMPRISING AN AUXILIARY RECEPTACLE FOR HOLDING OIL AND REFRIGERANT GAS, A VACUUM PUMP, A REFRIGERANT SUPPLY TANK, A MANIFOLD CONNECTED SEPARATELY TO THE HIGH OR DISCHARGE SIDE OF THE AUTOMOBILE COMPRESSOR, THE REFRIGERANT SUPPLY TANK, AND THE AUXILIARY TANK; MEANS FOR SELECTIVELY CONNECTING EITHER THE REFRIGERANT SUPPLY TANK OR THE VACUUM PUMP WITH THE MID-PORTION OF THE MANIFOLD, VALVE MEANS CLOSING THE MID-PORTION OF THE MANIFOLD FROM EACH END THEREOF, AN OPEN TOPPED VERTICAL REFRIGERANT CHARGING TUBE WITHIN THE AUXILIARY RECEPTACLE EXTENDING ABOVE THE LIQUID LEVEL OF THE OIL THEREIN, PIPING CONNECTING THE BOTTOM OF THE AUXILIARY RECEPTACLE WITH THE SUCTION SIDE OF THE COMPRESSOR, SAID PIPING INCLUDING VALVE MEANS FOR CONNECTING THE AUTOMOBILE COMPRESSOR WITH EITHER THE CHARGING TUBE TO DISCHARGE REFRIGERANT GAS TO THE AUTOMOBILE COMPRESSOR OR TO THE BOTTOM OF THE AUXILIARY RECEPTACLE TO DISCHARGE OIL TO THE COMPRESSOR WHEREBY OIL MAY BE DISCHARGED TO THE COMPRESSOR WITHOUT OPENING THE SYSTEM TO THE ATMOSPHERE. 